High Def and Standard Def
Standard Def video (SD) is video as it has been since the invention of television. In the United States, this meant NTSC video (National Television Standards Committee) and in Europe, Asia, and many other areas, PAL (Phase Alternating Line). Secam is another format used in France and the former USSR. NTSC consists of 525 scan lines from top to bottom in each frame and approximately 30 frames per second. PAL is 625 lines per frame and 50 frames per second. Officially, NTSC is now being replaced as a broadcast standard in the United States, Mexico, and Canada by ATSC (Advanced Television Standards Committee).
Standard Def video will soon be part of history as it is gradually giving way to High-definition ...